key scientific studies on trap-neuter-return

7/27/2019 Key Scientific Studies on Trap-Neuter-Return

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Fact Sheet

www.alleycat.org 7920 Norfolk Avenue, Suite 600 Bethesda, MD 20814-2525 2012

KEY SCIENTIFIC STUDIES ON

TRAP-NEUTER-RETURN

Cats benet from Trap-Neuter-Return for theirentire lives.Studies show that after neutering, cats become healthier andgain weight. Outdoor cats in managed colonies even livelonger thanks to TNR. One study of a TNR program foundthat at the end of a 10-year period, 83% of the cats in themanaged colonies had been residing in those colonies formore than six yearsindicating a lifespan comparable to the7.1-year lifespan of pet cats.

Neutered cats also roam less and do not ght over mates.Studies have found that after neutering, cats in managedcolonies were less aggressive and more aectionate towardseach other.

By eliminating mating behaviors, Trap-Neuter-Return makes cats better neighbors.Neutered cats make less noise, for example, and ght less.One study found that calls to animal control about catsdecreased after a TNR program was implementedeventhough the human population increased.

Multiple long-term studies of Trap-Neuter-Return have shown that the size of managedcolonies decreases over time.One study found a 66% decrease in the populations ofmanaged colonies over 11 years, while another study of aTNR program over a 10-year period documented colony sizedecreases of 16 to 32%.StudiesFinkler, Hilit, Erez Hatna, and Joseph erkel. Te impactof anthropogenic factors on the behavior, reproduction,management and welfare of urban, free-roaming catpopulations.Anthrozos24, no. 1(2011):31-49.

e research in this article indicates that TNR and colonycare improves cats lives by reducing their stress levels. Whilelooking at the correlation between the level of care providedby cat caregivers and the economic status of the area in whichthe cats live, the authors observed that neutered male cats

were less aggressive than intact males. By testing the levels ofstress hormone in their hair, they conrmed the neutered catslower stress levels. ey also found that spayed female catsliving in well-maintained colonies experienced less stress thanthose living in colonies that received less care.

Research

Scientic studies show that Trap-Neuter-Return, also known as TNR, is the humane and effective

approach for managing feral cats. Trap-Neuter-Return improves the lives of feral cats, improves

their relationships with the people who live near them, and decreases the size of colonies over time.

These studies have been conducted in multiple countries, and have been published in a variety of

peer-reviewed scientic journals.


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Fact Sheet:


KEY SCIENTIFIC STUDIES ON TRAP-NEUTER-RETURN, page 2 of 3

Finkler, Hilit, Idit Gunther, and Joseph erkel. Behavioraldierences between urban feeding groups of neutered andsexually intact free-roaming cats following a trap-neuter-return procedure.Journal of the American Veterinary

Medical Association 238, no. 9 (2011):1141-1149.

Researchers compared data from four feral cat colonies: twothat were cared for through Trap-Neuter-Return programsand two that were not and demonstrated that TNR reducesthe behaviors associated with mating and can thereforeaddress community concerns. ey found that cats in theTNR colonies were less aggressive on the whole and that theneutered males were rarely aggressive towards each other at all,

resulting in less yowling, ghting, and potential for injury thanmales in the intact colonies.

Hughes, Kathy L. and Margaret R. Slater.Implementation of a Feral Cat Management Program ona University Campus.Journal of Applied Animal WelfareScience5, no. 1 (2002): 15-28.

Hughes and Slater document the success of a new Trap,Test, Vaccinate, Alter (spay or neuter), Return, and Monitor(TTVARM, a.k.a. TNR) program on the campus of Texas

A&M University, looking at the changes between theimplementation year and the year that followed. In the rstyear, 123 cats were trapped, compared to 35 in the second.Over the course of the program, 32 cats and kittens wereadopted. In the second year, only three kittens were found,and the researchers assume that these were lost or abandoned,as no litters or nursing mothers were seen in that year. eprogram illustrated how a well-managed TNR program canstabilize a population of cats.http://www.societyandanimalsforum.org/jaaws/full_articles/5.1/hughes.pdf

Hughes, Kathy L., Margaret R. Slater, and Linda Haller. TeEects of Implementing a Feral Cat Spay/Neuter Programin a Florida County Animal Control Service.Journal ofApplied Animal Welfare Science5 (2002): 285-289.

e authors analyzed data from a feral cat spay/neuterprogram that included a volunteer-based program to carefor feral cat colonies in Orange County, Florida, against thepopulation of the county for the six years before the programbegan and the rst six years of the program. ey found that

both the number of calls to animal control about cats andthe number of cats killed by animal control decreased inthe six years after these programs were initiated, even whilethe human population grew signicantly. In addition, theyreported that the morale of those involved improved, and theresidents who participated in the program felt empoweredto make a positive impact on the lives of feral cats in theirneighborhoods.http://www.societyandanimalsforum.org/jaaws/full_articles/5.4/hughes.pdf

Levy, Julie K., David W. Gale, and Leslie A. Gale.

Evaluation of the Eect of a Long-erm rap-Neuter-Return and Adoption Program on a Free-Roaming CatPopulation.Journal of the American Veterinary Medical

Association 222, no. 1 (2003): 42-46.

is study tracks a TNR program on a Florida college campusover the course of 11 years to determine the characteristicsof cats involved and to document the eectiveness of theprogram at controlling the population of cats on the campus.Kittens and tame cats wereadopted out, and new cats

were trapped and neutered.

At the end of the study, thepopulation had decreasedby 66%, and over 80% ofthe cats had been residentsfor more than six yearsaduration comparable to themean lifespan of 7.1 yearsfor pet cats.http://www.avma.org/avmacollections/feral_cats/javma_222_1_42.pdf

Natoli, Eugenia, et. al. Management of Feral DomesticCats in the Urban Environment of Rome (Italy).Preventative Veterinary Medicine77 (2006): 180-185.

is study documents the cat population over 10 years in awell-established Trap-Neuter-Return program in Rome, Italy,and determines that a long-term TNR program signicantlyreduces feral cat colony size. Colony size consistentlydecreased over the time period, ranging from a 16% declinein colonies neutered three years into the program to a 32%

JEFFLENARD
http://www.societyandanimalsforum.org/jaaws/full_articles/5.1/hughes.pdfhttp://www.societyandanimalsforum.org/jaaws/full_articles/5.1/hughes.pdfhttp://www.societyandanimalsforum.org/jaaws/full_articles/5.4/hughes.pdfhttp://www.societyandanimalsforum.org/jaaws/full_articles/5.4/hughes.pdfhttp://www.societyandanimalsforum.org/jaaws/full_articles/5.1/hughes.pdfhttp://www.societyandanimalsforum.org/jaaws/full_articles/5.1/hughes.pdfhttp://www.societyandanimalsforum.org/jaaws/full_articles/5.1/hughes.pdfhttp://www.societyandanimalsforum.org/jaaws/full_articles/5.1/hughes.pdfhttp://www.societyandanimalsforum.org/jaaws/full_articles/5.1/hughes.pdfhttp://www.societyandanimalsforum.org/jaaws/full_articles/5.1/hughes.pdfhttp://www.societyandanimalsforum.org/jaaws/full_articles/5.4/hughes.pdfhttp://www.societyandanimalsforum.org/jaaws/full_articles/5.4/hughes.pdfhttp://www.societyandanimalsforum.org/jaaws/full_articles/5.1/hughes.pdfhttp://www.societyandanimalsforum.org/jaaws/full_articles/5.1/hughes.pdf


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Fact Sheet:


KEY SCIENTIFIC STUDIES ON TRAP-NEUTER-RETURN, page 3 of 3

decrease in colonies neutered six years into the program. Also,as the program became more visible, the number of registeredferal cat colonies increased from 76 to 965. e authorscaution that community education is crucial to preventingintact pet cats from joining the stray and feral cat population.http://www.kiccc.org.au/pics/Study_FeralCatsRome2006.pdf

Neville, P.F. and J. Remfry. Eect of Neutering on woGroups of Feral Cats. Te Veterinary Record114 (1984):447-450.

Researchers studied two colonies in Regents Park, London, todetermine whether neutering had any negative eects eitheron the social structure of the colony or on the individual cats.No negative health eects were observed, and the colonyssocial structure seemed to strengthen after the cats wereneutered. Cats were seen to spend more time in groups, showfewer aggressive behaviors toward each other, and ght less.http://veterinaryrecord.bvapublications.com/cgi/content/abstract/114/18/447

Scott, Karen C., Julie K. Levy, and Shawn P. Gorman.Body Condition of Feral Cats and the Eect ofNeutering.Journal of Applied Animal Welfare Science5,no. 3 (2002): 203-213.

is study examines the eects of neutering on feral cathealth by measuring the body condition of feral cats upontrapping, then measuring it again for 14 cats who weretrapped again one year later. e cats who were trappedinitially were lean but not emaciated, and the cats trappedone year after neutering showed signicant increases in weightand improvements in body condition. In addition, caregiversreported that the cats had a decreased tendency to roam after

being neutered.http://www.societyandanimalsforum.org/jaaws/full_articles/5.3/scott.pdf
http://www.kiccc.org.au/pics/Study_FeralCatsRome2006.pdfhttp://www.kiccc.org.au/pics/Study_FeralCatsRome2006.pdfhttp://veterinaryrecord.bmj.com/content/114/18/447.abstracthttp://veterinaryrecord.bmj.com/content/114/18/447.abstracthttp://www.societyandanimalsforum.org/jaaws/full_articles/5.3/scott.pdfhttp://www.societyandanimalsforum.org/jaaws/full_articles/5.3/scott.pdfhttp://www.societyandanimalsforum.org/jaaws/full_articles/5.3/scott.pdfhttp://www.societyandanimalsforum.org/jaaws/full_articles/5.3/scott.pdfhttp://veterinaryrecord.bmj.com/content/114/18/447.abstracthttp://veterinaryrecord.bmj.com/content/114/18/447.abstracthttp://www.kiccc.org.au/pics/Study_FeralCatsRome2006.pdfhttp://www.kiccc.org.au/pics/Study_FeralCatsRome2006.pdf

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